594 research outputs found
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Energy productivity and efficiency of wheat farming in Bangladesh
Wheat is the second most important cereal crop in Bangladesh and production is highly sensitive to variations in the environment. We estimate productivity and energy efficiency of wheat farming in Bangladesh by applying a stochastic production frontier approach while accounting for the environmental constraints affecting production. Wheat farming is energy efficient with a net energy balance of 20,596 MJ per ha and energy ratio of 2.34. Environmental constraints such as a combination of unsuitable land, weed and pest attack, bad weather, planting delay and infertile soils significantly reduce wheat production and its energy efficiency. Environmental constraints account for a mean energy efficiency of 3 percentage points. Mean technical efficiency is 88% thereby indicating that elimination of inefficiencies can increase wheat energy output by 12%. Farmers' education, access to agricultural information and training in wheat production significantly improves efficiency, whereas events such as a delay in planting and first fertilization significantly reduce it. Policy recommendations include development of varieties that are resistant to environmental constraints and suitable for marginal areas; improvement of wheat farming practices; and investments in education and training of farmers as well as dissemination of information
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Environmental constraints and profitability relationships in agriculture: a case study of wheat farming in Bangladesh
This article attempts to measure the influence of environmental constraints on profitability and resource use in agriculture by utilizing survey data of 293 wheat farmers from three regions of Bangladesh. Analysis is based on a profit function, where the selected variables representing environmental constraints were incorporated as additional fixed factors. Results revealed that environmental constraints have a significant influence on both profitability and farmers’ resource allocation decisions. Output supply and input demands were significantly affected by land suitability and other environmental constraints (i.e. a combination of poor soil fertility, pest and weed infestation and weather variation). The policy implications include development of wheat varieties that are suitable for low lying and/or marginal areas, are resistant to insect and pest attacks and can withstand weather variations. Also, soil fertility improvement through soil conservation and crop rotation, improvement in managerial practices through extension services and strengthening of research–extension link will improve profitability
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Impact of environmental production conditions on productivity and efficiency: a case study of wheat farmers in Bangladesh.
Environmental conditions significantly affect production, but are often ignored in studies analysing productivity and efficiency leading to biased results. In this study, we examine the influence of selected environmental factors on productivity and efficiency in wheat farming in Bangladesh. Results reveal that environmental production conditions significantly affect the parameters of the production function and technical efficiency, as well as correlates of inefficiency. Controlling for environmental production conditions improves technical efficiency by 4 points (p<0.01) from 86% to 90%. Large farms are more efficient relative to small and medium sized farms (p<0.01 and 0.05), with no variation among regions. Policy implications include soil fertility improvement through soil conservation and crop rotation, improvement in managerial practices through extension services and adoption of modern technologies, promotion of education, strengthening the research-extension link, and development of new varieties that have higher yield potential and are also suitable for marginal areas
The contribution of turmeric research and development In the economy of Bangladesh: an ex-post analysis
The study estimated the benefit and rates of returns to investment on turmeric research and development in Bangladesh. The Economic Surplus Model with ex-post analysis was used to determine the returns to investment and their distribution between the production and consumption. Several discounting techniques were also used to assess the efficiency of turmeric research. The adoption rate was found increasing trend over the period. The yield of BARI developed modern varieties of turmeric was 41 to 73% higher than those of the local variety. Society got net benefit Tk. 9333.88 million from the investment of turmeric research and extension. The net present value (NPV) and present value of research cost (PVRC) were estimated at Tk. 1200.84 and 157.88, respectively. The internal rate of return (IRR) and benefit cost ratio (BCR) were estimated to be 68% and 10.45, respectively indicated investment on turmeric research and development was a good and profitable investment. Seed production programme of turmeric should be taken largely to increase production by increasing area adoption. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.20968 Int. J. Agril. Res. Innov. & Tech. 4 (1): 1-10, June, 201
Generalized optimal step-size for blind multichannel LMS system identification
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Diastolic And Systolic Right Ventricular Dysfunction Precedes Left Ventricular Dysfunction In Patients Paced From Right Ventricular Apex
Background: Cardiac dysfunction after right ventricular (RV) apical pacing is well known but its extent, time frame of appearance and individual effect on left ventricular (LV), RV systolic and diastolic parameters has not evaluated in a systematic fashion.
Methods: Patients with symptomatic bradycardia and ACC-AHA Class I indication for permanent pacemaker implantation (PPI) were implanted a single chamber (VVI) pacemaker. They were followed prospectively by echocardiographic examination which was done at baseline, 1 week, 1 month and 6 months after implantation. Parameters observed were chamber dimensions (M-line), chamber volumes, cardiac output (modified Simpson's method), systolic functions (ejection fraction, pre-ejection period, ejection time and ratio) and diastolic functions( isovolumic relaxation time & deceleration time) of left and right heart.
Results: Forty eight consecutive patients (mean age 65.6±11.8 yrs, 66.7% males, mean EF 61.82±10.36%) implanted a VVI pacemaker were enrolled in this study. The first significant change to appear in cardiac function after VVI pacing was in diastolic properties of RV as shown by increase in RV isovolumic relaxation time (IVRT) from 65.89±15.93 to 76.58±17.00 ms,(p<0.001) at 1week and RV deceleration time (DT) from 133.84±38.13 to 153.09±31.41 ms, (p=0.02) at 1 month. Increase in RV internal dimension (RVID) from 1.26±0.41 to 1.44±0.44, (p<0.05) was also noticed at 1 week. The LV diastolic parameters were significantly altered after 1 month with increase in LV-IVRT from 92.36±21.47 to 117.24±27.21ms, (p<0.001) and increase in LV DT from 147.56±31.84 to 189.27±28.49ms,(p<0.01). This was followed by LV systolic abnormality which appeared at 6 months with an increase in LVPEP from 100.33±14.43 to 118.41±21.34ms, (p<0.001) and increase in LVPEP/LVET ratio from 0.34±0.46 to 0.44±0.10, (p<0.001)]. The reduction in LV EF was manifested at 6 months falling from 61.82±10.36% to52.52±12.11%, (p<0.05) without any significant change in the resting cardiac output.
Conclusion: The present study shows that dysfunction of right ventricle is the first abnormality that occurs in VVI paced patients, which manifests by 1 week followed by LV dysfunction which starts appearing by 1 month and the diastolic dysfunctions precede the systolic dysfunction in both ventricles
Prevalence and Demographic, Socioeconomic, and Behavioral Risk Factors of Self-Reported Symptoms of Sexually Transmitted Infections (STIs) among Ever-Married Women: Evidence from Nationally Representative Surveys in Bangladesh
Sexually transmitted infections (STI) symptoms (e.g., abnormal genital discharge and genital sores/ulcers) are a major public health concern in Bangladesh because the symptoms can indicate an STI and cause sexual and reproductive health complications in women of reproductive age. To our knowledge, no study examined the prevalence and risk factors of STI symptoms using a nationally representative sample. This study investigates the prevalence of STI symptoms among ever-married women in Bangladesh and the associations of STI symptoms with various demographic, socioeconomic, and behavioral risk factors using the most recent available data (2007, 2011, and 2014) of the Bangladesh Demographic and Health Surveys (BDHS). The BDHS employs a two-stage stratified sampling technique. The analytic sample comprised 41,777 women of reproductive age (15–49 years). Outcome variables included STI symptoms: abnormal genital discharge and genital sores/ulcers. Multivariate logistic regression was employed to find the adjusted odds ratio with a 95% confidence interval to assess the associations of outcome measures with explanatory variables. The study found that the prevalence of abnormal genital discharge and genital sores/ulcers among ever-married women aged 15–49 years was 10% and 6%, respectively. Multi-variable analysis revealed that for women aged 25–34 years, those who used contraceptives and married earlier had an increased likelihood of STI symptoms. Furthermore, women from the wealthiest wealth quintile and couple’s joint decision-making were less likely to have STI symptoms. Findings have implications for interventions efforts aiming to improve women’s sexual and reproductive health in Bangladesh
Utilization of High Volume Fraction of Binary Combinations of Supplementary Cementitious Materials in the Production of Reactive Powder Concrete
The reactive powder concrete (RPC) is one of the special concrete types that characteristics with high cement content which means high production cost and CO2 emissions to the atmosphere. Therefore, to enhance the environment as well as to develop green RPC, alternatives to cement, such as supplementary cementitious materials (SCMs) were used. Limited studies addressed the use of a high volume fraction of SCMs as a binary combination in the production of RPC. Thus, this study aims to replace a high percentage of cement (50%) with binary combinations of silica fume (SF), type F fly ash (FA) and metakaolin (MK). The experimental program included two phases. In phase one, two groups (SF+FA and MK+FA) were cast without steel fibers. Based on group performance in the first phase, one group was chosen to be used with steel fibers in the second phase. The flow rate, compressive and flexural strengths, density, ultrasonic pulse velocity and dynamic modulus of elasticity tests were conducted. The phase one results showed that SF+FA combination mixtures had better performance than MK+FA mixtures thus they were selected to be used in the second phase (with the addition of 1% volumetric fraction micro steel fibers). Results indicated that it is possible to produce sustainable RPC in which the cement can be replaced with 30% SF and 20% FA (the total replacement is 50%) in the presence of 1% steel fibers with a remarkable enhancement in compressive strength and flexural strength reached up to 44% and 10%, respectively
Hepatitis C infection and clearance: impact on atherosclerosis and cardiometabolic risk factors
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